The effect of solanine on the membrane potential of mitochondria in HepG2 cells and [Ca2+]i in cells

To observe the effect of solanine on the membrane potential of mitochondria in HepG₂ cells and [Ca²⁺]_i in the cells, and to uncover the mechanism by which solanine induces apoptosis.HepG₂ cells are double stained with AO/EB, and morphological changes of the cells are observed using laser confocal scanning microscopy (LCSM). HepG₂ cells are stained with TMRE, and changes in the membrane potential of mitochondria in the cells are observed using LCSM. HepG² cells are double stained with Fluo-3/AM, and change of [Ca²⁺]_i in the cells are observed using LCSM. HepG² cells are double stained with TMRE and Fluo-3/AM, and both the change in membrane potential of mitochondria and that of [Ca²⁺]_i in the cells are observed using LCSM. Cells in treated groups show typical signs of apoptosis. The results of staining with TMRE show that solanine can lower membrane potential; those of staining with Fluo-3/AM show that solanine can increase the concentration of Ca²⁺ in tumor cells; and those of double staining with TMRE and Fluo-3/AM show that solanine can lower membrane potential; those of staining with TMRE show that solanine can increase the concentration of Ca²⁺ in the cells at the same time as it lowers the membrane potential of mitochondria. Solanine opens up the PT channels in the membrane by lowering the membrane potential, leading to Ca²⁺ being transported down its concentration gradient, which in turn leads to the rise of the concentration of Ca²⁺ in the cell, turning on the mechanism for apoptosis.